The invention pertains to a process for the continuous production of solids, especially protein concentrates, from aqueous solutions, in particular blood, the solution being brought in contact with superheated steam.
Protein concentrates from aqueous solutions, in particular so-called blood meal from animal blood, are used for a variety of purposes. Thus blood concentrates made from animal blood in the form of the so-called blood albumin is an important raw material in the production of binders. Besides, dried blood meal is being used more and more frequently to feed animals or as nitrogen-containing fertilizer in agriculture and horticulture. Because it must be assumed that the animal blood carries microorganisms, regulations have been decreed which specify that the blood must be sterilized before or during processing, in order thereby to supress the spread of pestilences and diseases.
In a known process of the kind described above, the animal blood is sterilized by admission of steam at a temperature of about 130.degree. C., and is caused to coagulate at the same time. Then, the separated serum is centrifuged and the residual substance is dried.
Apart from the fact that a biological decomposition of the blood occurs due to the steam treatment, which takes about 30 minutes, and that the drying leads to an undesirable pollution of the environment by unpleasant odors, the known process has the further disadvantage that the separated serum cannot be discharged into the sewer system directly, but must first be processed.